/Engine/Plugins/Importers/USDImporter/Source/USDClasses/Public/USDAssetUserData.h
We assign these to UStaticMeshes or USkeletalMeshes generated from USD
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)() class UUsdMeshAssetUserData : public [UUsdAssetUserData](API\Plugins\USDClasses\UUsdAssetUserData)
TMap< int32,FU...
MaterialSlotToPrimPaths
Maps from a material slot index of anUStaticMeshorUSkeletalMeshto a list of source prims that contain this assignment.
TMap<FString, ...
PrimvarToUVIndex
Describes which primvars should be assigned to each UV index.